1. Field of the Invention
The present invention generally relates to disc cartridges and, more particularly, is directed to a disc cartridge for cleaning an objective lens of a disc drive apparatus of an optical disc recording and reproducing apparatus for recording and/or reproducing discs, such as an optical disc, a magneto-optical disc and so on.
2. Description of the Prior Art
In a recent optical disc system, in order to protect a signal recording surface of a disc, an optical disc cartridge system is realized, in which an optical disc is accommodated within a disc cartridge and the optical disc is loaded onto a disc drive apparatus, thereby being recorded and/or reproduced under the condition such that the optical disc is accommodated within the disc cartridge.
In this optical disc cartridge system, when the disc cartridge is repeatedly loaded onto the disc drive apparatus, an objective lens of an optical pickup device within the disc drive apparatus is smudged by dust or the like. There is then the risk that the normal recording and/or reproduction will be hindered.
To remove such disadvantage, various cartridge type cleaners for cleaning the objective lens of the optical pickup, i.e., a cartridge for cleaning an objective lens, have been proposed so far. For example, brushes are implanted on the outer surface of, for example, an ordinary disc cartridge and this cartridge is inserted into the disc drive apparatus so that, after the loading operation is finished, an optical pickup device is moved to clean its objective lens; and brushes are implanted on a disc accommodated within a cartridge and this cartridge is inserted into the disc drive apparatus so that, after the loading operation is finished, the disc is rotated to clean the objective lens.
However, the above-mentioned previously-proposed cleaning cartridge is of the type such that the objective lens is cleaned by utilizing the movement of the optical pickup device or by utilizing the rotation of the disc, so that in such case the cleaning operation needs an electrical driving force. In other words, if the power switch of the disc drive apparatus is not turned ON, the cleaning operation cannot be performed. Further, in the latter cleaning cartridge utilizing the rotation of the disc, the disc is rotated at high speed, and unavoidably, there is then the risk that the objective lens will be damaged by the brushes, which brings about a serious problem in actual practice.
To solve the aforementioned problems, the assignee of the present application has previously proposed the following cleaning cartridge (see Japanese Utility Model Application No. 1-42568).
According to this previously-proposed cleaning cartridge, there is provided a disc drive optical pickup cleaning cartridge which utilizes a disc cartridge having a correct insertion detecting portion by which when the disc cartridge is correctly inserted into the disc drive apparatus, a disc cartridge locking mechanism is operated to lock the thus inserted disc cartridge. This cleaning cartridge is provided with a cleaning member, for example, a brush formed along the insertion direction of the cartridge and is not provided with the correct insertion detecting portion.
When this cleaning cartridge is inserted into the disc drive side, the top of the brush comes in contact with the objective lens of the optical pickup device to clean the objective lens. Further, the correct insertion detecting portion is not to provided so that, if the cartridge is inserted into the innermost portion, the cartridge is not locked and ejected again. By this loading and/or unloading operation of the cartridge, the optical pickup device can be cleaned without the electrical driving force.
In the thus constructed cleaning cartridge, the brush is secured to the cartridge as the cleaning member and is also protruded from the outer surface of the cartridge so that, when the cartridge is inserted into the disc drive apparatus, the brush is brought in contact with a member which is located at the insertion entrance side relative to the objective lens, e.g., a disc turntable or the like. As a consequence, before removing smudges of the objective lens, the brush is smudged by dust or the like on the turntable, dust within an opening portion of the turntable shaft or the like. There is then the risk that the objective lens will be smudged by such dust or the like.